Electric series terminal

ABSTRACT

An electric series terminal having a releasable and insertable isolating plug with an insulated grip portion and a metallic contact portion. The plug has two connecting devices for electric conductors and the terminal itself comprises an insulating body with various contacting parts therein.

i United States Patent Inventor Appl. No.

Filed Patented Assignee Priority ELECTRIC SERIES TERMINAL Hans Woertzuasdyswiuefland 193,195,196, 206, 20 210, 6,153 783320 [56] 7 ReferencesCited a; 3' 3;? UNITED STATES PATENTS 1011,639 12/1911 Murray etal.339/19X Messrs. Oskar Woe lnh. H. 8.- woeflz "Z, 1,363,224 12/ 1920Birch 339/19 X Basel, Switzerland FOREIGN PATENTS F21 13,1968 1,370,1097/1964 France 339/198 (.41) graz g a Primary Examiner-Marvin A. ChampionAssistant ExaminerRobert A. Hafer A!t0rneyWatson, Cole, Grindle & Watson8 Chums Drawing ABSTRACT: An electric series terminal having areleasable US. Cl 339/198, and in nable i olating lug with an insulatedgrip portion and l 196 a metallic contact portion. The plug has twoconnecting Iiiv H01! devices for electric conductors and the terminalitself com- Fleld of Search 339/ 19, prises an insulating body withvarious contacting parts therein.

This invention relates to an electric series terminal with a releasablyinsertable isolating plug.

. It is an object of the present invention to provide an electric seriesterminal with a releasably insertable isolating plug having an insulatedgrip portion and a metallic contact portion, which'latter portioninterconnects two connecting devices for electric conductors and thesedevices are arranged in an insulating body.

in a known series terminal of the stated type, the contact portion ofthe isolating plug comprises two pairs of fingers, disposed parallelwith each other and each of which, for the purpose of connecting the twoconnecting devices, resiliently embraces a projecting contact part ofsaid devices, the areas of contact between the plug fingers and thecontact part being relatively small. Thus, in the case of heavycurrents, rather severe heating can occur.

A further object of the present invention basically consists in avoidingthe above-mentioned disadvantages. For this purpose, the series terminalof the invention is essentially characterized in that each of theconnecting devices comprises an angular contact part with one limb ofone contact part being disposed at a distance from and parallel to thecorresponding limb of the other contact part. The faces of the twoparallel limbs of the contact parts facing away from each other lyingagainst the insulating body, and such faces of the two stated limbsfacing each other being in contact with corresponding opposed faces onthe contact portion of the inserted isolating plug.

Further objects and details of the invention will be apparent from thefollowing description of one embodiment when considered in connectionwith the accompanying drawing in which:

FIG. 1 is a side elevation, partly in section, of a series terminal, thecap of the insulating body being removed;

FIG. 2 is a side view taken in the arrow direction ll of FIG. 1;

HO. 3 is a cross section taken on the line lll-lll of FIG. 1 in thedirection of the arrows;

FIG. 4 is a side view of the isolating plug; and

P16. 5 is a side view of the inside of the cap of the insulating body.

As shown in the drawing, the series terminal comprises a two-partinsulating body 10, a relatively small cap 13 being completely sunk ordepressed into a complementary recess 11 in the larger part 12 of theinsulating body, which part 12 will be referred to hereinafter as thebase. Inserted in the base 12 are two connecting devices 14, in whichthe ends of electric conductors can be firmly clamped. Each connectingdevice 14 incorporates a clamping element 15, which consists of a pieceor section of rectangular tube displaceably mounted in the base 12.Positioned in the tub is one limb 16 of a contact part 17 bent at rightangles and this limb acts as a pressure element. The other limb 18 ofthe contact part 17 runs parallel with the direction in which theclamping element is displaced. As can be seen from FIG. I, the two limbs18 of the contact parts 17 are disposed parallel with each other, andportions of the limbs 16, acting as pressure elements, are coaxial inthe longitudinal direction. Each contact device 14 also incorporates asocket-hand screw 19,. which is screwed into a tapped hole in theclamping element 15 and bears with its end on the middle portion of thelimb 16 of the contact part. Since the head of the screw 19 bearsagainst a shoulder 20 in a recess 21 in the base 12, provided forturning the screw 19, and the contact part 17 is held againstdisplacement in the base 12 in a manner to be described, the effect ofturning the screw 19 is to displace the clamping element 15 relativelyto the limb 16. To increase the clamping action on the conductors to beheld in the connecting devices 14, that side of the limb 16 remote fromthe end of the screw 19 has a longitudinal groove 22. F urthermore, forthe same purpose, a saddle shaped spring element 75 23 with angled endportions is fitted in the conductor-receiving compartment of eachclamping element 15.

For electrically connecting the limbs 18, there is provided a isolatingplug 24, FlGS. 1 and 4, which comprises an insulated grip portion and aone-piece bifurcated contact portion having two plug pins 26, which arein spaced-apart parallel relationship and are of rectangular crosssection. The contact portion of the isolating plug 24 is pressed intoits grip portion 25 and the plug pins 26 are spread slightly, HO. 4,when the isolating plug 24 is withdrawn from the insulating body 10.

The longitudinal grooves 22 in the shanks 16 of the contact parts 17,acting as pressure elements or surfaces are continued into the mutuallyfacing sides of the parallel limbs 18 and over the entire lengththereof, and such lateral faces of the plug pins 26 of the insertedisolating plug 24 that face away from each other, extend partially intothe continued grooves and are in contact with the bottoms thereof. Ascan be seen from FIG. 3, except for the grooved longitudinal faceportions of the parallel limbs 18 with which the plug pins 26 are incontact, all the other longitudinal face portions bearagainst walls ofcomplimentary recesses in the insulating body 10. Grooves 27 and 28,matched to the cross section and length of the shanks 18, are providedboth in the base 12 and in the cap 13, so that both the base 12 and thecap 13 each embrace about one-half of those faces of the parallel limbs18 of the contact parts 17 that face away from each other. Since thelengths of the above-mentioned grooves 27 and 28 correspond to thelengths of the limbs 18 and, in addition, the ends of the limbs 16 eachabut against a nose 29 on the base 12, displacement or twisting of thecontact parts 17, relatively to the base 12 or the cap 13, is precluded.

The cap 13 also incorporates between the parallel limbs 18 of thecontact part, a longitudinal rib 30 against which those faces of theplug pins 26 that face each other, bear. The iongitudinal rib 30 on thecap 13 engages in a complimentary groove 31 in the base 12.

In the present embodiment, the base 12 and the cap 13 are made of athermoplastic synthetic material. The two parts of the insulating bodycan therefore be interconnected by molding. For this purpose, the tonguelike lower end portion of the cap 13 is provided with an orifice 32through which is pushed a cylindrical stud 33 on the base 12. The end ofthe stub 33 is welded to the cap 13 by the application of heat andpressure.

To prevent the plug pins 26 from being inadvertently contacted when theisolating plug 24 is being inserted or withdrawn, the grip portion 25incorporates sleeves 34 each of which surrounds the upper end of pinsplug pin 26. When the isolating plug 24 is inserted, the two sleeves 34are fully engaged in a complimentary recess 35 in the base 12.

The important advantage of the above-described series terminal andreleasably insertable isolating plug resides in the fact that thecontact surfaces of the plug pins are of large area and are in contactwith the corresponding opposed faces of the contact parts underrelatively high pressure. The contact resistance at the 'points ofcontact is thereby kept small, so that even under heavy current loading,no impermissibly great heating occurs. The high contact pressure isachieved by the longitudinal faces of the parallel limbs of the contactparts lying against the walls of the insulating body and by thespreading action of the plug pins being reinforced by the longitudinalrib 30 on the cap-l3.

When the isolating plug is withdrawn, the longitudinal rib 30, disposedbetween the parallel limbs of the contact parts, considerably increasesthe creepage path distance between the contact parts. Furthermore, thecap 13 which embraces the parallel limbs of the contact parts on thoseof their longitudinal faces turned away from each other, counteractsdeflection of the base l2 resulting from the contact pressure of theisolating plug, and in addition, due to the cap 13 being connected tothe base- 12, the metal parts of the connection devices 14 are heldfirmly in the insulating body in a manner that prevents their beinglost.

In a modified form of the series terminal, not illustrated in thedrawing, the shanks l6 and 18 of the contact parts do not containlongitudinal grooves for centering the electric conductors or forguiding the plug pins 26. Despite this simplification, the good contactproperties are retained, since the plug pins cannot deflect laterally.Furthermore, the cap 13 can be connected to the base 12 by gluinginstead of welding.

lclaim:

1. Electric series terminal with a releasably insertable isolating plug,comprising an insulated grip portion and a metallic contact portion,said metallic contact portion interconnecting two connecting devices forelectric conductors, and insulating body in which the devices arearranged, each of the connecting devices comprising an angular contactpart having two limbs, one limb thereof being disposed at a distancefrom and colinear with a corresponding limb of the other contact parts,the other two corresponding limbs being parallel and being against theinsulating body, and an inserted isolated plug with those faces of thetwo parallel limbs facing each other being in contact with correspondingopposed faces on a contact portion of the inserted isolating plug, andsaid corresponding limbs of the contact parts engaging in complimentarygrooves in the insulating body.

2. Electric series terminal with a releasably insertable isolating plug,comprising an insulated grip portion and a metallic contact portion,said metallic contact portion interconnecting two connecting devices forelectric conductors, an insulating body in which the devices arearranged, each of the connecting devices comprising an angular contactpart having two limbs, one limb thereof being disposed at a distancefrom and colinear with a corresponding limb of the other contact parts,the other two corresponding limbs being parallel and being against theinsulating body, and an inserted isolating plug with those faces of thetwo parallel limbs facing each other being in contact with correspondingopposed faces on a contact portion of the inserted isolating plug andexcept for the longitudinal face portions with which the contact portionof the isolating plug is in contact, all the other longitudinal faceportions of the parallel limbs of the other contact parts bear againstwalls of complimentary recesses in the insulating body.

3. Electric series terminal according to claim 2, in which theinsulating body is composed of two parts of which one part being a capwhich is completely depressed in a complimentary recess in the otherpart of the insulating body, and the complimentary recesses against thewalls of which the parallel limbs be being present in both parts of theinsulating body so that the cap partially embraces those faces of theparallel limbs of he other contact part that face away from each other.

4. Electric series terminal according to claim 2, in which theinsulating body is composed of two parts of which one part being a capwhich is completely depressed in a complimentary recess in the otherpart ofthe insulating body, and the complimentary recesses against thewalls of which the parallel limbs of the other contact parts lies, beingpresent in both parts of the insulating body so that the cap partiallyembraces those faces of the parallel limbs of the other contact partthat face away from each other, and the cap being welded to the otherpart of the insulating body.

5. Electric series terminal with a releasably insertable isolating plug,comprising an insulating grip portion and a metallic contact portion,said metallic contact portion interconnecting two connecting devices forelectric conductors, an insulating body in which the devices arearranged, each of the connecting devices comprising an angular contactpart having two limbs, one limb thereof being disposed at a distancefrom and colinear with a corresponding limb of the other contact parts,the other two corresponding limbs being parallel and being against theinsulting body, and an inserted isolating plug with those faces of thetwo parallel limbs facing each other being in contact with thecorresponding opposed faces on a contact portion of the insertedisolating plug, a contact part of the isolating plug comprises two plugpins in spaced-apart parallel relationshi with each other, said plugpins being interconnected in t e insulated grip portion of the isolatingplug, and the insulating body comprises a rib against which the mutuallyfacing faces of the plug pins bear between the parallel limbs of thecontact part.

6. Electric series terminal according to claim 5, in which the rib formspart of the cap disposed between the plug pins and the rib engaging in acomplimentary groove in the other part of the insulating body.

7. Electric series terminal with a releasably insertable isolating plug,comprising an insulated grip portion and a metallic contact portion,said metallic contact portion interconnecting two connecting devices forelectric conductors, an insulating body in which the devices arearranged, each of the connecting devices comprising an angular contactpart having two limbs, one limb-thereof being disposed at a distancefrom and colinear with a corresponding limb of the other contact parts,the other two corresponding limbs being parallel and being against theinsulating body, and an inserted isolating plug with those faces of thetwo parallel limbs facing each other being in contact with correspondingopposed faces on a contact portion of the inserted isolating plug, acontact part of the isolating plug comprises two plug pins inspaced-apart parallel relationship with each other, said plug pins beinginterconnected in the insulated grip portion of the isolating plug, theplug pins being of rectangular cross section, and the mutually facingsides of the parallel limbs of the contact parts containing longitudinalgrooves into which the plug pins at least partially extend.

8. Electric series terminal according to claim 7, in which thelongitudinal grooves in the parallel limbs of the other contact partsbeing continued in the other limbs thereof, which latter limbs arearranged as pressure elements, in a tubular clamping element of eachconnecting device.

1. Electric series terminal with a releasably insertable isolating plug,comprising an insulated grip portion and a metallic contact portion,said metallic contact portion interconnecting two connecting devices forelectric conductors, and insulating body in which the devices arearranged, each of the connecting devices comprising an angular contactpart having two limbs, one limb thereof being disposed at a distancefrom and colinear with a corresponding limb of the other contact parts,the other two corresponding limbs being parallel and being against theinsulating body, and an inserted isolated plug with those faces of thetwo parallel limbs facing each other being in contact with correspondingopposed faces on a contact portion of the inserted isolating plug, andsaid corresponding limbs of the contact parts engaging in complimentarygrooves in the insulating body.
 2. Electric series terminal with areleasably insertable isolating plug, comprising an insulated gripportion and a metallic contact portion, said metallic contact portioninterconnecting two connecting devices for electric conductors, aninsulating body in which the devices are arranged, each of theconnecting devices comprising an angular contact part having two limbs,one limb thereof being disposed at a distance from and colinear with acorresponding limb of the other contact parts, the other twocorresponding limbs being parallel and being against the insulatingbody, and an inserted isolating plug with those faces of the twoparallel limbs facing each other being in contact with correspondingopposed faces on a contact portion of the inserted isolating plug andexcept for the longitudinal face portions with which the contact portionof the isolating plug is in contact, all the other longitudinal faceportions of the parallel limbs of the other contact parts bear againstwalls of complimentary recesses in the insulating body.
 3. Electricseries terminal according to claim 2, in which the insulating body iscomposed of two parts of which one part being a cap which is completelydepressed in a complimentary recess in the other part of the insulatingbody, and the complimentary recesses against the walls of which theparallel limbs be being present in both parts of the insulating body sothat the cap partially embraces those faces of the parallel limbs of heother contact part that face away from each other.
 4. Electric seriesterminal according to claim 2, in which the insulating bOdy is composedof two parts of which one part being a cap which is completely depressedin a complimentary recess in the other part of the insulating body, andthe complimentary recesses against the walls of which the parallel limbsof the other contact parts lies, being present in both parts of theinsulating body so that the cap partially embraces those faces of theparallel limbs of the other contact part that face away from each other,and the cap being welded to the other part of the insulating body. 5.Electric series terminal with a releasably insertable isolating plug,comprising an insulating grip portion and a metallic contact portion,said metallic contact portion interconnecting two connecting devices forelectric conductors, an insulating body in which the devices arearranged, each of the connecting devices comprising an angular contactpart having two limbs, one limb thereof being disposed at a distancefrom and colinear with a corresponding limb of the other contact parts,the other two corresponding limbs being parallel and being against theinsulting body, and an inserted isolating plug with those faces of thetwo parallel limbs facing each other being in contact with thecorresponding opposed faces on a contact portion of the insertedisolating plug, a contact part of the isolating plug comprises two plugpins in spaced-apart parallel relationship with each other, said plugpins being interconnected in the insulated grip portion of the isolatingplug, and the insulating body comprises a rib against which the mutuallyfacing faces of the plug pins bear between the parallel limbs of thecontact part.
 6. Electric series terminal according to claim 5, in whichthe rib forms part of the cap disposed between the plug pins and the ribengaging in a complimentary groove in the other part of the insulatingbody.
 7. Electric series terminal with a releasably insertable isolatingplug, comprising an insulated grip portion and a metallic contactportion, said metallic contact portion interconnecting two connectingdevices for electric conductors, an insulating body in which the devicesare arranged, each of the connecting devices comprising an angularcontact part having two limbs, one limb thereof being disposed at adistance from and colinear with a corresponding limb of the othercontact parts, the other two corresponding limbs being parallel andbeing against the insulating body, and an inserted isolating plug withthose faces of the two parallel limbs facing each other being in contactwith corresponding opposed faces on a contact portion of the insertedisolating plug, a contact part of the isolating plug comprises two plugpins in spaced-apart parallel relationship with each other, said plugpins being interconnected in the insulated grip portion of the isolatingplug, the plug pins being of rectangular cross section, and the mutuallyfacing sides of the parallel limbs of the contact parts containinglongitudinal grooves into which the plug pins at least partially extend.8. Electric series terminal according to claim 7, in which thelongitudinal grooves in the parallel limbs of the other contact partsbeing continued in the other limbs thereof, which latter limbs arearranged as pressure elements, in a tubular clamping element of eachconnecting device.